ChemSphere
23V50.942

Vanadium

Transition metal · Period 4 · Group 5 · d-block

The steel-strengthening metal with a rainbow of oxidation states

Atomic mass
50.942 u
State at 25 °C
Solid
Electronegativity
1.63
Melting point
1,909.9 °C
Boiling point
3,406.9 °C
Configuration
[Ar] 3d3 4s2
Building atom…
23 protons 28 neutrons 23 electrons

Vanadium, explained

Video lesson in production

Bhavya’s explainer for this element will play here.

Overview

Vanadium ([Ar]3d3 4s2) can give up two, three, four or five electrons, and each oxidation state has its own color in solution: violet V2+, green V3+, blue VO2+ (vanadyl) and yellow VO2+ (the dioxovanadium(V) ion). The color changes come from the different numbers of d electrons left behind, and in the case of V5+, from none at all. Because vanadium moves easily between oxidation states, its oxide V2O5 is an excellent redox catalyst and is used to make most of the world's sulfuric acid.

The pure metal is hard, silvery gray and melts at 1910 °C. About 85 percent of vanadium goes into steel, usually added as ferrovanadium. Just 0.1 to 0.3 percent vanadium forms tiny, hard carbide and nitride particles that refine the steel's grain, giving high strength without brittleness, ideal for rebar, pipelines and chrome-vanadium hand tools. A growing share now goes into vanadium redox flow batteries, which store grid electricity using vanadium ions in both halves of the cell.

Discovery

Andrés Manuel del Río found the element in 1801 in a Mexican lead ore, now called vanadinite, and named it erythronium, but he was persuaded that it was merely impure chromium. In 1830 Nils Gabriel Sefström rediscovered it in Swedish iron ore and named it after Vanadís, a name of the Norse goddess Freyja, for the beauty of its colorful compounds. Henry Roscoe isolated the metal in 1867 by reducing vanadium chloride with hydrogen.

Where it’s found
Present at about 0.01–0.02 percent of the crust, vanadium is recovered mostly from slag produced when smelting vanadium-bearing magnetite iron ores, chiefly in China, Russia and South Africa, and also from oil residues.
What it’s used for
  • High-strength steel
  • Chrome-vanadium tools
  • Sulfuric acid catalyst
  • Grid-scale flow batteries
  • Titanium aerospace alloys
In living things
Vanadium is not proven to be essential for humans. Some organisms do use it, including bacteria with vanadium nitrogenase and seaweeds with vanadium-containing haloperoxidase enzymes.
Safety
Vanadium pentoxide dust irritates the eyes and lungs and is classified as a possible human carcinogen. The bulk metal is of low hazard.

How it compares

Where Vanadium sits among all 118 elements on the trends that shape the table.

  • Electronegativity1.63Pauling

    #48 of 100 elements with data

  • Ionization energy651kJ/mol

    #56 of 104 elements with data

  • Atomic radius135pm

    #59 of 95 elements with data

  • Electron affinity50.9kJ/mol

    #52 of 109 elements with data

  • Density6g/cm³

    #74 of 114 elements with data

  • Melting point2,180K

    #15 of 110 elements with data

Density
6 g/cm³
Atomic radius
135 pm
Covalent radius
134 pm
Molar heat
24.89 J/(mol·K)
Appearance
blue-silver-grey metal
Discovered by
Andrés Manuel del Río

Inside the atom

23 electrons arranged in 4 shells: 2 · 8 · 11 · 2.

Orbital diagram

1s2 2s2 2p6 3s2 3p6 4s2 3d3 · shorthand [Ar] 3d3 4s2

  1. 1s2
  2. 2s2
  3. 2p6
  4. 3s2
  5. 3p6
  6. 4s2
  7. 3d3

Each box is an orbital holding up to two electrons of opposite spin. Highlighted subshells hold the valence electrons that decide how Vanadium bonds.

Ionization energies

Energy to remove each electron in turn, on a log scale. The biggest leap, from electron 21 to 22 (×4.4), is where the next electron has to come from a filled shell much closer to the nucleus.

Signature reactions

The chemistry Vanadium is known for.

  1. Catalysis · Industrial

    Contact process for sulfuric acid

    Vanadium(V) oxide oxidizes sulfur dioxide and is then re-oxidized by oxygen, cycling between +5 and +4 without being used up. The sulfur trioxide is absorbed to make sulfuric acid, the most-produced industrial chemical in the world.

    2SO2(g)+O2(g)2SO3(g)

    Conditions: V2O5 catalyst, 400–450 °C, about 1–2 atm

  2. Redox · Color change

    Zinc reduction rainbow

    A yellow vanadium(V) solution shaken with zinc in acid turns blue, then green, then violet as vanadium is reduced step by step from +5 to +2. It is a classic demonstration of variable oxidation states in transition metals.

    2VO2+(aq)+3Zn(s)+8H+(aq)2V2+(aq)+3Zn2+(aq)+4H2O(l)

    Conditions: zinc amalgam or granules in acid

  3. Redox · Electrochemistry

    Flow battery discharge

    In a vanadium redox flow battery, V(V) is reduced at the positive side while V(II) is oxidized at the negative side, giving about 1.26 volts per cell. Because both tanks contain vanadium, cross-contamination does not ruin the electrolyte, so the batteries can last for decades.

    VO2+(aq)+V2+(aq)+2H+(aq)VO2+(aq)+V3+(aq)+H2O(l)

    Conditions: sulfuric acid electrolyte, separated by a membrane

Where you’ll meet it

  • Vanadinite

    Vanadinite

    Vanadinite, a lead chlorovanadate, forms bright red-orange hexagonal crystals and was the ore in which vanadium was first found.

    Photo: Wikimedia Commons
  • Vanadium redox battery

    Vanadium redox battery

    Large vanadium flow batteries store solar and wind energy for the electricity grid.

    Photo: Wikimedia Commons
  • Damascus steel

    Damascus steel

    Studies suggest trace vanadium in Indian wootz steel helped create the famous watered patterns on Damascus blades.

    Photo: Wikimedia Commons
  • Fly agaric

    Fly agaric

    The fly agaric mushroom concentrates vanadium in a compound called amavadin.

    Photo: Wikimedia Commons

Research

No research on Vanadium yet

When Bhavya publishes a project that studies Vanadium, it will be linked here.

See all research